CN117782994A

CN117782994A - Tab detection system and tab detection method

Info

Publication number: CN117782994A
Application number: CN202410200679.2A
Authority: CN
Inventors: 徐小伟; 马林; 胡良锦
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2024-02-23
Filing date: 2024-02-23
Publication date: 2024-03-29
Anticipated expiration: 2044-02-23

Abstract

The application relates to a tab detection system and a tab detection method. The tab detection system includes: a control unit that outputs a photographing control signal to the imaging unit and a driving control signal to the driving unit; the imaging unit is used for shooting the lug through the prism unit to obtain a lug image; and a prism device including: a prism table; a prism unit which projects an image of the tab to the imaging unit by refraction, and is disposed on the prism table so as to be movable with respect to the prism table; a driving unit that moves and/or rotates the prism unit relative to the prism table, the control unit iteratively performing the following operations until it is determined that the difference between the evaluation parameter of the tab image and the first threshold value is not outside a predetermined range: sending a shooting control signal to an imaging unit; calculating the tab image to obtain an evaluation parameter; and in response to determining that the difference between the evaluation parameter and the first threshold is outside a predetermined range, moving and/or rotating the prism unit relative to the prism table by a prescribed step size.

Description

Tab detection system and tab detection method

Technical Field

The application relates to the field of battery detection, in particular to a tab detection system and a tab detection method for detecting tabs of a battery.

Background

In the assembly process of the lithium battery, the production process of the battery cell mainly comprises two processes of winding and lamination. In both winding and lamination processes, the thicknesses of the tabs (for example, the tabs are made of aluminum foil or copper foil) of the cathode and the anode of the battery cell are only in the micron level, so that the strength is relatively low, and the tabs of the cathode and the anode may be folded and damaged in the production process of the battery cell. For this reason, there is currently a device for detecting the state of the battery tab by using an imaging detection device. An important link for such imaging detection devices is to acquire images of the tabs with a camera. However, since it is difficult to directly photograph the inner and outer sides of the tab because the pitch of the battery cell tab is too small, a prism device is generally used to obtain a tab image. However, in the conventional imaging detection apparatus, it is necessary to manually adjust the relative positional relationship between the prism and the tab to obtain a clear image. Such manual adjustment can take a lot of time and effort and is largely dependent on experience, knowledge and subjective knowledge of the operator, so that it is difficult to accurately, objectively and automatically obtain a clear tab image.

Disclosure of Invention

In view of the above, the present application provides a tab detection system and a tab detection method capable of quickly and clearly obtaining a tab image.

In a first aspect, the present application provides a tab detection system, which is characterized in that the tab detection system includes: a control unit that outputs a photographing control signal to the imaging unit and a driving control signal to the driving unit; the imaging unit is used for shooting the tab through the prism unit according to the shooting control signal to obtain a tab image; and a prism device, the prism device comprising: a prism table; a prism unit that projects an image of the tab to the imaging unit by refraction and is disposed to be movable with respect to the prism table; and a driving unit that moves and/or rotates the prism unit with respect to the prism table according to a driving control signal of the control unit, wherein the control unit is configured to iteratively perform the following operation until it is determined that a difference between an evaluation parameter of the tab image and a first threshold value is not outside a predetermined range: sending a shooting control signal to the imaging unit; calculating the tab image shot by the imaging unit to obtain an evaluation parameter of the tab image; and outputting a drive control signal to the drive unit to move and/or rotate the prism unit relative to the prism table by a prescribed step size in response to determining that the difference between the evaluation parameter and the first threshold value is outside a predetermined range.

In the technical scheme of the embodiment of the application, the control unit automatically judges whether the currently shot tab image meets the preset requirement or not, and the prism unit is automatically adjusted under the condition that the preset requirement is not met until the prism unit can shoot the clear tab image, so that manual adjustment is not needed, a great deal of manpower and energy are not needed, and the clear tab image can be quickly and automatically obtained.

In some embodiments, the control unit comprises: the upper computer is used for controlling the imaging unit to shoot the tab image, responding to the tab image shot by the imaging unit, calculating the tab image to obtain an evaluation parameter of the tab image and sending the evaluation parameter to the lower computer; and a lower computer provided to the prism device, which determines whether a difference between the evaluation parameter and a first threshold value is out of a predetermined range in response to receiving the evaluation parameter from the upper computer, and if the difference between the evaluation parameter and the first threshold value is out of the predetermined range, outputs a driving control signal to the driving unit so that the prism unit moves and/or rotates at a prescribed step length with respect to the prism table, and transmits a request requesting the imaging unit to capture an image to the upper computer.

In the technical scheme of the embodiment of the application, the upper computer performs overall control of the system and operation processing with larger operation amount, and the lower computer performs control on the corresponding prism device according to the operation result of the upper computer, so that more complex embedded system functions can be realized.

In some embodiments, the driving unit includes: a translation direction driving device for moving the prism unit along a translation direction; and a rotation direction driving device that rotates the prism unit around a central axis of the prism unit.

In some embodiments, a chute is provided at the prism stage, the chute extending along the translation direction, the translation direction driving device comprising: the sliding block is arranged on the sliding groove in a sliding manner; and a translation driver for moving the slider along the chute in the translation direction according to a driving control signal of the control unit, the rotation direction driving device including a rotation driver for rotating the prism unit around a central axis of the prism unit according to the driving control signal of the control unit, and the rotation driver being provided to the slider.

In some embodiments, the translation direction is a length direction of the prism table, and the central axis is perpendicular to a face direction of the prism table.

In some embodiments, the prism unit includes a prism support, a prism lens, and a central shaft, one end of the central shaft is connected to the prism support, and the other end is rotatably disposed on the slider.

In some embodiments, the prism apparatus further comprises a cleaning apparatus, and the control unit is further configured to: and outputting a cleaning control signal to the cleaning device to enable the cleaning device to clean the prism unit when the evaluation parameter is smaller than or equal to a second threshold value.

In the technical scheme of the embodiment of the application, the tab detection system can automatically judge the time for executing the cleaning treatment without manual intervention, so that the working efficiency is improved. In addition, the prism unit can be cleaned even in a non-stop state, and the efficiency of photographing can be improved.

In some embodiments, the cleaning device comprises: a wiper strip in contact with the prism unit; and a cleaning driver for moving the wiper strip in a predetermined direction according to the cleaning control signal to clean the prism unit.

In some embodiments, the prism device further includes a damper device provided on a first side of the prism table, the first side being a different side from a second side on which the prism unit is disposed, the prism device being fixed to the tab detection system via the damper device.

In the technical scheme of this application embodiment, through setting up damping device for come from the vibration of utmost point ear detecting system or outside and be filtered, avoid appearing imaging degradation such as ghost image, lose burnt when imaging, thereby can shoot clear utmost point ear image.

In some embodiments, the control unit controls the driving unit to reset at least one of a position or a rotation angle of the prism unit with respect to the prism table to a predetermined value before detecting the tab.

In the technical scheme of the embodiment of the application, before the tab is detected, the control unit controls the driving unit to reset at least one of the position or the rotation angle of the prism unit relative to the prism table to the preset value, so that the posture of the prism unit can be initialized to the default optimal posture, the time required for shooting a clear tab image is shortened, and the corresponding preset values can be set for different battery types.

In some embodiments, the prism apparatus includes a first prism unit having a first drive unit and a second prism unit having a second drive unit, the first and second prism units configured to measure the positive and negative tabs, respectively.

In the technical scheme of this application embodiment, can detect the anodal utmost point ear and the negative pole utmost point ear of battery simultaneously, can shorten shooting time, improve work efficiency.

In some embodiments, the control unit controls the first prism unit and the second prism unit to reset at a preset angle, resets the first prism unit and the second prism unit to a preset position according to a difference between the tabs, rotates the first prism unit and the second prism unit in a first rotation direction and/or moves the first prism unit in a first translation direction to increase the distance in response to determining that the difference between the evaluation parameter and the first threshold is out of a preset range, adjusts at a preset angle and/or a preset distance each time, and rotates the first prism unit and the second prism unit in a second rotation direction opposite to the first rotation direction and/or moves the first prism unit in a second translation direction opposite to the first translation direction in response to determining that the evaluation parameter of tab images obtained after adjusting the first prism unit and the second prism unit is larger than the difference between the first threshold.

In a second aspect, the present application provides a tab detection method, which is applied to a tab detection system, where the tab detection system includes a control unit, an imaging unit, and a prism device, where the imaging unit is configured to capture a tab to obtain a tab image, and the prism device includes: a prism table; a prism unit that projects an image of the tab to the imaging unit by refraction and is disposed to be movable with respect to the prism table; and a driving unit that moves and/or rotates the prism unit with respect to the prism table according to a driving control signal of the control unit, the tab detection method including: iteratively performing the following operations until it is determined that the difference between the evaluation parameter of the tab image and the first threshold value is not outside a predetermined range: shooting the tab by the imaging unit to obtain the tab image; calculating the tab image by the control unit to obtain an evaluation parameter of the tab image; and controlling, by a control unit, the prism unit to move and/or rotate in a prescribed step size relative to a prism stage of the prism apparatus in response to determining that the difference between the evaluation parameter and the first threshold value is outside a predetermined range.

According to the technical scheme, whether the currently shot tab image meets the preset requirement or not can be automatically judged, and the prism unit is automatically adjusted under the condition that the preset requirement is not met until the prism unit can shoot the clear tab image, so that manual adjustment is not needed, a great deal of manpower and energy are not needed, and the clear tab image can be quickly and automatically obtained.

In some embodiments, the control unit comprises: the upper computer is used for controlling the imaging unit to shoot images; and the lower computer is arranged on the prism device, and the tab detection method comprises the following steps: the upper computer responds to the lug image shot by the imaging unit, calculates the lug image to obtain an evaluation parameter of the lug image and sends the evaluation parameter to the lower computer, the lower computer responds to the evaluation parameter received from the upper computer, judges whether the difference between the evaluation parameter and a first threshold value is out of a preset range or not, and if the difference between the evaluation parameter and the first threshold value is out of the preset range, a control signal is output to the driving unit so that the prism unit moves and/or rotates at a preset step length relative to the prism table, and sends a request for requesting the imaging unit to shoot an image to the upper computer.

In some embodiments, the prism device further comprises a cleaning device, and when the evaluation parameter is equal to or less than a second threshold value, the control unit outputs a cleaning control signal to the cleaning device so that the cleaning device cleans the prism unit.

In some embodiments, the drive unit is controlled by the control unit to reset at least one of the position or the rotation angle of the prism unit relative to the prism table to a predetermined value prior to detection of the tab.

In some embodiments, the control unit controls the first prism unit and the second prism unit included in the prism unit to reset at a preset angle, resets the first prism unit and the second prism unit to a preset position according to a distance between the tabs, rotates the first prism unit and the second prism unit in a first rotation direction and/or moves the first prism unit in a first translation direction to increase the distance in response to determining that a difference between the evaluation parameter and a first threshold is out of a preset range, adjusts at each preset angle and/or a preset distance, and rotates the first prism unit and the second prism unit in a second rotation direction opposite to the first rotation direction and/or moves the first prism unit in a second translation direction opposite to the first translation direction in response to determining that the evaluation parameter of the tab image obtained after adjusting the first prism unit and the second prism unit is larger than the difference between the first threshold.

The foregoing description is only an overview of the technical solutions of the present application, and may be implemented according to the content of the specification in order to make the technical means of the present application more clearly understood, and in order to make the above-mentioned and other objects, features and advantages of the present application more clearly understood, the following detailed description of the present application will be given.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the application. Also, like reference numerals are used to designate like parts throughout the accompanying drawings. In the drawings:

fig. 1A is a schematic view showing the tab a in a folded state.

Fig. 1B is a schematic view showing the tab a in another folded state.

Fig. 1C is a schematic view showing the tab a in another folded state.

Fig. 1D is a schematic view showing the tab a in another folded state.

Fig. 1E is a schematic view showing the tab a in another folded state.

Fig. 1F is a schematic view showing the tab a in another folded state.

Fig. 1G is a schematic view showing the tab a in another folded state.

Fig. 1H is a schematic view showing the tab a in another folded state.

Fig. 2 is a block diagram illustrating functional modules of a tab detection system disclosed in one embodiment of the present application.

Fig. 3 is a block diagram illustrating functional modules of a tab detection system disclosed in one embodiment of the present application.

Fig. 4 is a structural perspective view illustrating a prism device of a tab detection system disclosed in one embodiment of the present application.

Fig. 5 is a structural plan view showing a prism device of the tab detection system disclosed in one embodiment of the present application.

Fig. 6 is a structural front view illustrating a prism device of a tab detection system disclosed in one embodiment of the present application.

Fig. 7 is a structural front view showing a prism device of the tab detection system disclosed in one embodiment of the present application.

Fig. 8 is a structural perspective view illustrating a prism device of a tab detection system disclosed in one embodiment of the present application.

Fig. 9 is a flowchart illustrating a tab detection method of one embodiment of the present disclosure.

Fig. 10 shows a control logic diagram of an exemplary lower computer of the prism apparatus.

Reference numerals in the specific embodiments are as follows:

1: a tab detection system; 2: a battery; 11: a control unit; 12: an imaging unit; 13: a prism device; 131: a prism table; 132: a prism unit; 132A: a first prism unit; 132B: a second prism unit; 133: a driving unit; 133A: a first driving unit; 133B: a second driving unit; 1331: a translational direction driving device; 1332: a rotation direction driving device; 1311: a chute; 1333: a slide block; 1334: a translation driver; 1335: a rotary driver; 1321: a prism support; 1322: a prism lens; 1323: a center shaft; 134: a cleaning device; 15: a damping device; 1341: a wiping strip; 1342: a cleaning drive.

Detailed Description

Embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical solutions of the present application, and thus are only examples, and are not intended to limit the scope of protection of the present application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description and claims of the present application and in the description of the figures above are intended to cover non-exclusive inclusions.

In the description of the embodiments of the present application, the technical terms "first," "second," etc. are used merely to distinguish between different objects and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, a particular order or a primary or secondary relationship. In the description of the embodiments of the present application, the meaning of "plurality" is two or more unless explicitly defined otherwise.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of the present application, the term "and/or" is merely an association relationship describing an association object, which means that three relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

In the description of the embodiments of the present application, the term "plurality" refers to two or more (including two), and similarly, "plural sets" refers to two or more (including two), and "plural sheets" refers to two or more (including two).

In the description of the embodiments of the present application, the orientation or positional relationship indicated by the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of describing the embodiments of the present application and for simplifying the description, rather than indicating or implying that the apparatus or element referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the embodiments of the present application.

In the description of the embodiments of the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured" and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally formed; or may be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the embodiments of the present application will be understood by those of ordinary skill in the art according to the specific circumstances.

In the assembly process of the lithium battery, the production process of the battery cell mainly comprises two processes of winding and lamination. In both winding and lamination processes, the thicknesses of the tabs (for example, the tabs are made of aluminum foil or copper foil) of the cathode and the anode of the battery cell are only in the micron level, so that the strength is relatively low, and the tabs of the cathode and the anode can be folded and damaged in the production process of the battery cell. Fig. 1A to 1H are schematic views showing the tab a in a folded state. Fig. 1A to 1H show eight folded states of the tab, which are merely examples and not exhaustive. As shown in fig. 1A, in the first folded state C1 of the tab a, the tab a is folded by the fold angle, but is not folded to the coating film region B. As shown in fig. 1B, in the second folded state C2 of the tab a, the tab a is folded by a corner, and is folded to the coating region B. As shown in fig. 1C, in the third folded state C3 of the tab a, the tab a is folded so as to be parallel to the boundary between the tab and the coating region, but is not folded to the coating region B. As shown in fig. 1D, tab a is folded parallel to the boundary between the tab and the coating region, and is folded into coating region B. As shown in fig. 1E, tab a is folded by overlapping and folding, but is not folded to coating region B. As shown in fig. 1F, tab a is folded by overlapping and folding, and folded to coating region B. As shown in fig. 1G, a part of the tab a is folded over to the coating region B. As shown in fig. 1H, tab a is fully folded over to coating region B. In the tab folding state shown in fig. 1B, 1D, 1F, 1G and 1H, since the tab has been folded to the coating region, the formed battery cell may have low capacity, short circuit, thermal failure, and other phenomena after being fabricated into a battery, which affects the safety of the battery. In the tab folded state shown in fig. 1A, 1C, and 1E, the tab is not folded into the coating region, but there is a risk of folding into the coating region or poor tab welding during subsequent processing.

For this reason, there is currently a device for detecting the state of the battery tab by using an imaging detection device. An important link for such imaging detection devices is to acquire a clear tab image with a camera. However, since it is difficult to directly photograph the inside and outside of the tab with an imaging device because the pitch of the battery cell tab is too small, a prism device is generally used to obtain an image of the tab. However, in the existing imaging detection apparatus, the relative positions of the prism and the tab need to be manually adjusted to obtain a clear image. For example, an operator firstly stops the padlock of the equipment, then manually adjusts the fixing position screw of the prism to adjust the relative position of the prism and the lug, locks the screw after the adjustment is finished, and then checks the imaging quality of the camera, and the process is repeated until the optimal state determined by the operator is reached. Such manual adjustment can take a lot of time and effort and is too dependent on experience, judgment and subjective knowledge of the operator, making it difficult to quickly and automatically obtain a clear tab image.

The present inventors have noted such a problem and have provided a tab detection system and method that can quickly and automatically obtain a clear tab image. The tab detection system and method of the present disclosure may be applied to, for example, detection on a product line of a battery such as a lithium battery.

Fig. 2 is a block diagram illustrating functional modules of a tab detection system disclosed in one embodiment of the present application. As shown in fig. 2, the tab detection system 1 includes a control unit 11, an imaging unit 12, and a prism device 13. The tab detection system 1 can be used for shooting the tabs of the battery 2 on the product line to obtain clear tab images. The control unit 11 outputs a photographing control signal to the imaging unit 12, and outputs a driving control signal to the driving unit 133 of the prism device 13. The imaging unit 12 photographs the tab via the prism unit 132 in accordance with a photographing control signal from the control unit 11 to obtain a tab image. The prism apparatus 13 includes a prism stage 131, a prism unit 132, and a driving unit 133. The prism table 131 is used for carrying the prism unit 132 and the driving unit 133. The prism table 131 may have any shape such as a plate shape and a table shape. The prism unit 132 projects an image of the tab to the imaging unit 12 by refraction, and is disposed on the prism table 131 in a movable manner with respect to the prism table 131. The driving unit 133 moves and/or rotates the prism unit 132 with respect to the prism table 131 according to a driving control signal of the control unit 11. The control unit 11 is configured to iteratively perform the following operations until it is determined that the difference between the evaluation parameter of the tab image captured by the imaging unit 12 and the first threshold value is not outside the predetermined range: sending a photographing control signal to the imaging unit 12; calculating the tab image shot by the imaging unit 12 to obtain an evaluation parameter of the tab image; and outputting a driving control signal to the driving unit 133 to move and/or rotate the prism unit 132 with respect to the prism table 131 by a prescribed step size in response to determining that the difference between the evaluation parameter and the first threshold value is outside the predetermined range.

For example, the battery 2 manufactured on the product line is conveyed to the position to be detected by the conveying device, and the prism unit 132 is disposed at a preset initial position. First, the control unit 11 of the tab detection system 1 outputs a photographing control signal to the imaging unit 12. The imaging unit 12 receives the photographing control signal, photographs the tab via the prism unit 132 to obtain a tab image, and then the tab image is transmitted to the control unit 11. Next, the control unit 11 calculates an evaluation parameter of the photographed tab image, and determines whether or not a difference between the calculated evaluation parameter and the first threshold value is out of a predetermined range. Determining that the calculated evaluation parameter is not outside the predetermined range means that the tab image currently photographed is considered to be an image satisfying the predetermined requirement; otherwise, the current shot tab image is an image which does not meet the preset requirement. In the case where it is determined that the difference between the calculated evaluation parameter and the first threshold value is out of the predetermined range (the tab image currently photographed does not satisfy the predetermined requirement), the control unit 11 outputs a drive control signal to the drive unit 133 to move and/or rotate the prism unit 132 with respect to the prism table 131 by a prescribed step, thereby adjusting the posture of the prism unit 132 with respect to the tab of the battery 2. After the posture of the prism unit 132 is adjusted, the control unit 11 repeats the above-described operation until it is determined that the calculated difference between the evaluation parameter and the first threshold value is not outside the predetermined range. Here, the first threshold value may be an optimal value or a maximum value of an evaluation parameter for a specific type of battery, but is not limited thereto, and an operator may set according to actual needs. For example, the prism unit may be manually adjusted in advance for a specific type of battery to obtain a tab image satisfying a predetermined requirement, and the evaluation parameter calculated based on the tab image at that time may be stored as the first threshold. Further, the predetermined range may represent a deviation between an evaluation parameter allowing an actually photographed tab image and a first threshold value (e.g., a maximum value of the evaluation parameter). Due to many factors in the production line field environment (such as temperature, humidity, vibration, light illuminance, halation, etc.), there may be cases where the evaluation parameter cannot reach the maximum value regardless of the adjustment of the prism unit. Therefore, by setting the predetermined range, it is considered that the tab image photographed within the predetermined range has satisfied the predetermined requirement.

According to the tab detection system 1 of the present embodiment, the control unit automatically determines whether the currently photographed tab image meets the predetermined requirement, and automatically adjusts the prism unit 132 until the prism unit can photograph a clear tab image if the predetermined requirement is not met, so that manual adjustment is not required, a great deal of labor and effort are not required, and a clear tab image can be obtained quickly and automatically.

Fig. 3 is a block diagram illustrating functional modules of a tab detection system disclosed in one embodiment of the present application. According to one embodiment of the present application, the control unit 11 may optionally include an upper computer 111 and a lower computer 112. The upper computer 111 may be configured to control the imaging unit 12 to capture a tab image, and in response to the imaging unit 12 capturing the tab image, calculate the tab image to obtain an evaluation parameter of the tab image, and transmit the evaluation parameter to the lower computer 112. The lower computer may be provided to the prism device 13 and configured to determine whether a difference between the evaluation parameter and the first threshold value is outside a predetermined range in response to receiving the evaluation parameter from the upper computer 111, and if the difference between the evaluation parameter and the first threshold value is outside the predetermined range, output a drive control signal to the drive unit 133 to cause the prism unit 132 to move and/or rotate at a prescribed step size with respect to the prism table 131, and transmit a request to the upper computer 111 requesting the imaging unit 12 to capture an image. The host computer 111, upon receiving the request, transmits a shooting control signal to the imaging unit 12.

According to this embodiment, the control unit 11 may be implemented to include an upper computer 111 and a lower computer 112. The upper computer 111 may realize functions such as controlling the imaging unit 12, performing image processing, calculating evaluation parameters, and the like, and the lower computer 112 may control the driving unit 133 to adjust the posture of the prism unit 132 according to the image processing result, the evaluation parameters, and the like from the upper computer 111. By such configuration, the upper computer performs overall control of the system and calculation processing with a large amount of calculation, and the lower computer performs control of the corresponding prism device according to the calculation result of the upper computer, so that more complex embedded system functions can be realized.

Fig. 4 is a structural perspective view illustrating a prism device of a tab detection system disclosed in one embodiment of the present application. According to this embodiment, the driving unit 133 of the prism device 13 may optionally include a translational direction driving device 1331 and a rotational direction driving device 1332. The translation direction driving means 1331 moves the prism unit 132 in the translation direction by a predetermined step, and the rotation direction driving means 1332 rotates the prism unit 132 around the central axis of the prism unit 132 by a predetermined step.

According to this embodiment, by arranging the translational direction driving device 1331 and the rotational direction driving device 1332, the posture of the prism with respect to the tab can be adjusted in the translational direction and the rotational direction, thereby obtaining a clear tab image.

Fig. 5 is a structural plan view showing a prism device of the tab detection system disclosed in one embodiment of the present application. In this embodiment, the prism table 131 may be optionally provided with a slide groove 1311, the slide groove 1311 extending in the translational direction, the translational direction driving device 1331 including: a slider 1333 slidably provided in the chute 1311; and a translation driver 1334 for moving the slider 1333 in the translation direction along the chute 1311 according to a driving control signal of the control unit 11. Further, the rotation direction driving means includes a rotation driver 1335, and the rotation driver 1335 rotates the prism unit 132 around the central axis of the prism unit 132 according to a driving control signal of the control unit 11. In one embodiment, the rotary drive is provided to the slider 1333.

In one embodiment, alternatively, as shown in fig. 5, the translation direction may be a length direction (left-right direction in the drawing) of the prism table 131, and the center axis is perpendicular to the surface direction of the prism table 131.

In one embodiment, optionally, the evaluation parameter may include at least one of sharpness of the image, and pixel variance of the image. It should be understood that the evaluation parameter is not limited thereto, and any parameter that can characterize the imaging quality of a captured image may be used as the evaluation parameter. For example, as one example, the sharpness of an image may be characterized by a Brenner gradient function, which is a gradient evaluation function that computes the square of the gray difference between two adjacent pixels, defined as follows:

(1)

Wherein f (x, y) represents the gray value of the corresponding pixel point (x, y) of the image f, and D (f) is the calculation result of the image definition.

As another example, the sharpness of an image may also be characterized by an energy gradient function that sums the squares of the differences between gray values of adjacent pixels in the x-direction and the y-direction as a gradient value for each pixel point, and sums the gradient values for all pixels as a sharpness evaluation function value, expressed as follows:

(2)

Fig. 6 is a structural front view illustrating a prism device of a tab detection system disclosed in one embodiment of the present application. Fig. 7 is a structural front view showing a prism device of the tab detection system disclosed in one embodiment of the present application. In this embodiment, alternatively, the prism unit 132 may include a prism support 1321, a prism lens 1322, and a central shaft 1323, one end of the central shaft 1323 being connected to the prism support, and the other end being rotatably provided to the slider 1333. The side on which the prism lenses 1322 are arranged faces forward in fig. 6, and the side opposite to the side on which the prism lenses 1322 are arranged faces forward in fig. 7.

In one embodiment, the prism apparatus 13 may further include a cleaning apparatus 134, and the control unit 11 may output a cleaning control signal to the cleaning apparatus 134 to cause the cleaning apparatus 134 to clean the prism unit when the evaluation parameter is equal to or less than the second threshold value. In the tab detection field environment, the prism device 13 may be contaminated with contaminants such as dust, oil stain, etc., and a clear tab image may not be projected. Therefore, in the case where the evaluation parameter of the photographed tab image is equal to or less than the second threshold value indicating that the clear tab image cannot be projected due to contamination, the control unit 11 may activate the cleaning device 134 to clean the prism unit 132. The second threshold may be set as desired. In one embodiment, the cleaning device 134 may include: a wiper strip 1341 in contact with the prism unit 132; and a cleaning driver 1342 for moving the wiper strip in a prescribed direction according to the cleaning control signal to clean the prism unit 132. As shown in fig. 7, the cleaning drive 1342 may be disposed on the prism support 1321 opposite the side on which the prism lenses 1322 are disposed.

According to the embodiment of the application, the tab detection system can automatically judge the time for executing the cleaning process without manual intervention, so that the working efficiency is improved. In addition, the prism unit can be cleaned even in a non-stop state, and the efficiency of photographing can be improved.

Fig. 8 is a structural perspective view illustrating a prism device of a tab detection system disclosed in one embodiment of the present application. In this embodiment, the prism device 13 may further include a damper device 15, and the damper device 15 may be provided on a first side surface (upper surface in the drawing) of the prism table 131, which is a different side surface from a second side surface (lower surface in the drawing) on which the prism unit 132 is disposed, and the prism device 13 may be fixed to the tab detection system 1 via the damper device 15. In some embodiments, the shock absorbing device 15 may employ a shock absorbing ball, but is not limited thereto, as long as it is a member having a shock absorbing function. In some embodiments, one end of the damping device 15 may be fixed to a via hole provided in the prism table, and the other end is fixed to the tab detection system 1. In the field of tab detection, there are typically many sources of vibration, such as a conveyor mechanism for conveying the battery 2, a transfer mechanism for positioning the battery 2 in the area to be measured, and the like. Therefore, the prism device 13 may be affected by vibration or the like, and a ghost, a schlieren, or the like may appear in the image. According to the embodiment of the application, by arranging the damping device 15, vibration from the tab detection system 1 or the outside is filtered, imaging degradation such as ghosting, focus loss and the like during imaging is avoided, and therefore a clear tab image can be shot.

In one embodiment, the driving unit 133 may be optionally controlled by the control unit 11 to reset at least one of the position or the rotation angle of the prism unit 132 with respect to the prism table 131 to a predetermined value before the tab is detected. The predetermined value may be set according to the type of battery. The tab detection system 1 may store predetermined values of positions or rotation angles corresponding to types for different battery types in advance so that the posture of the prism unit 132 is initialized to a default optimal posture for the battery type, and then the tab detection system 1 adjusts to capture a clear tab image satisfying preset requirements. According to the embodiment of the present application, by controlling the driving unit by the control unit to reset at least one of the position or the rotation angle of the prism unit 132 with respect to the prism table to a predetermined value before the tab is detected, the posture of the prism unit can be initialized to the default optimal posture, thereby reducing the time required to take a clear tab image. Further, respective predetermined values can be set for different battery types.

In one embodiment, optionally, as shown in fig. 8, the prism device 13 includes two prism units: the first prism unit 132A and the second prism unit 132B, the first prism unit 132A and the second prism unit 132B having a first driving unit 133A and a second driving unit 133B, respectively, the first prism unit 132A and the second prism unit 132B being configured to measure the positive electrode tab and the negative electrode tab, respectively. The control unit 11 may individually control the first driving unit 133A and the second driving unit 133B. In addition, the corresponding imaging units 12 may be provided for the first prism unit 132A and the second prism unit 132B, respectively, or the tab images reflected by the first prism unit 132A and the second prism unit 132B may be simultaneously photographed with one imaging unit 12. Through this embodiment, can detect the anodal utmost point ear and the negative pole utmost point ear of battery 2 simultaneously, can shorten shooting time, improve work efficiency.

Further, in one embodiment, the control unit 11 controls the first prism unit 132A and the second prism unit 132B to be reset at a preset angle and to be reset at a preset position according to the pitch of the tabs, rotates and/or moves the first prism unit 132A and the second prism unit 132B in a first direction to increase the pitch in response to determining that the difference between the evaluation parameter and the first threshold is outside a predetermined range, adjusts at a preset angle and/or a preset distance each time, and rotates and/or moves the first prism unit 132A and the second prism unit 132B in a second direction opposite to the first direction in response to determining that the difference between the evaluation parameter of the tab image obtained after adjusting the first prism unit 132A and the second prism unit 132B is greater than the difference between the first threshold.

Fig. 9 is a flowchart illustrating a tab detection method of one embodiment of the present disclosure. The tab detection method of the present embodiment is applied to a tab detection system including a control unit, an imaging unit and a prism device, the imaging unit is used for capturing a tab via a prism unit of the prism device to obtain a tab image, and the prism device includes: a prism table; a prism unit that projects an image of the tab to the imaging unit by refraction and is disposed on the prism table so as to be movable with respect to the prism table; and a driving unit for moving and/or rotating the prism unit relative to the prism table according to a driving control signal of the control unit. As shown in fig. 9, the tab detection method according to one embodiment of the present disclosure includes the following steps:

step S901: and shooting the tab by an imaging unit to obtain a tab image.

Step S903: and calculating the tab image by a control unit to obtain the evaluation parameters of the tab image.

Step S905: it is determined whether the difference between the evaluation parameter and the first threshold value is outside a predetermined range.

Step S907: in response to determining that the difference between the evaluation parameter and the first threshold value is outside the predetermined range, the prism unit of the prism apparatus is controlled by the control unit to move and/or rotate relative to the prism stage of the prism apparatus by a prescribed step, and returns to step S901.

Step S909: and in response to determining that the difference between the evaluation parameter of the tab image and the first threshold is not outside the predetermined range, taking a clear tab image, and ending the process.

According to the tab detection method of the embodiment, whether the currently shot tab image meets the preset requirement can be automatically judged, and the prism unit is automatically adjusted under the condition that the preset requirement is not met until the prism unit can shoot the clear tab image, so that manual adjustment is not needed, a great deal of manpower and energy are not needed, and the clear tab image can be quickly and automatically obtained.

In one embodiment, optionally, the evaluation parameter may include at least one of sharpness of the image, and pixel variance of the image. It should be understood that the evaluation parameter is not limited thereto, and any parameter that can characterize the imaging quality of a captured image may be used as the evaluation parameter. For example, as one example, the sharpness of an image may be characterized by a Brenner gradient function. As another example, the sharpness of an image may also be characterized by an energy gradient function.

In one embodiment, optionally, the control unit may include an upper computer and a lower computer, the upper computer controls the imaging unit to capture an image, the lower computer is disposed on the prism device, and the tab detection method may further include: the upper computer responds to the lug image shot by the imaging unit, calculates the lug image to obtain an evaluation parameter of the lug image and sends the evaluation parameter to the lower computer, the lower computer responds to the received evaluation parameter from the upper computer, judges whether the difference between the evaluation parameter and the first threshold value is out of a preset range, if the difference between the evaluation parameter and the first threshold value is out of the preset range, a control signal is output to the driving unit so that the prism unit moves and/or rotates at a specified step length relative to the prism table, and sends a request for requesting the imaging unit to shoot the image to the upper computer.

According to this embodiment, the control of the control unit can be implemented as control including two parts of the upper computer and the lower computer. The control section of the upper computer may realize functions such as controlling the imaging unit, performing image processing, calculating evaluation parameters, and the like, and the control section of the lower computer may control the driving unit to adjust the posture of the prism unit in accordance with the image processing result, the evaluation parameters, and the like from the upper computer. By such a control method, the upper computer performs overall control of the system and calculation processing with a large amount of calculation, and the lower computer performs control of the corresponding prism device according to the calculation result of the upper computer, thereby realizing more complex embedded system functions.

In one embodiment, optionally, the prism device may further include a cleaning device, and in a case where the evaluation parameter is equal to or less than the second threshold value, a cleaning control signal may be output to the cleaning device by the control unit, so that the cleaning device cleans the prism unit. In the field environment of tab detection, the prism device may be contaminated by dust, oil stain and other contaminants, and cannot project a clear tab image. Therefore, when the evaluation parameter of the photographed tab image is equal to or less than the second threshold value indicating that the clear tab image cannot be projected due to contamination, the cleaning device may be activated to clean the prism unit.

In one embodiment, optionally, the driving unit may be controlled to reset at least one of the position or the rotation angle of the prism unit with respect to the prism table to a predetermined value before step S902. The predetermined value may be set according to the type of battery. The tab detection system 1 may store predetermined values of positions or rotation angles corresponding to types for different battery types in advance so that the posture of the prism unit 132 is initialized to a default optimal posture for the battery type, and then the tab detection system 1 adjusts to capture a clear tab image satisfying preset requirements. According to the embodiment of the present application, by controlling the driving unit by the control unit to reset at least one of the position or the rotation angle of the prism unit 132 with respect to the prism table to a predetermined value before the tab is detected, the posture of the prism unit can be initialized to the default optimal posture, thereby reducing the time required to take a clear tab image. Further, respective predetermined values can be set for different battery types.

In one embodiment, optionally, the first prism unit and the second prism unit included in the prism unit may be reset at a preset angle, the first prism unit and the second prism unit may be reset at preset positions according to a difference between the tab and the first threshold, the first prism unit and the second prism unit may be rotated in a first direction and/or moved in the first direction to increase the distance in response to determining that the difference between the evaluation parameter and the first threshold is outside a predetermined range, and each time the adjustment is performed at the preset angle and/or the preset distance, the evaluation parameter of the tab image obtained after the adjustment of the first prism unit and the second prism unit may be increased before the adjustment in response to determining that the difference between the evaluation parameter and the first threshold is compared with the difference between the tab image obtained after the adjustment of the first prism unit and the second prism unit, and the first prism unit may be rotated in a second direction and/or moved in the second direction.

Referring to fig. 8, a perspective view of one exemplary mechanical structure of a prism device is shown, according to some embodiments of the present application. In the present embodiment, a prism apparatus having two prism units (i.e., a first prism unit and a second prism unit) having respective corresponding driving units to drive respectively is shown, whereby the first prism unit and the second prism unit can photograph the positive electrode tab and the negative electrode tab of the battery at the same time, thereby shortening the photographing time.

As shown in fig. 8, in this embodiment, the prism device includes a prism table, a prism unit, a driving unit, a shock absorbing ball, and a cleaning device.

The prism unit comprises a prism lens, a prism support and a center shaft. The prism lens may be a plane mirror that reflects light, but is not limited thereto as long as an image of the tab can be projected to the imaging unit. The prism support is used for fixing and holding the prism lens. One end of the center shaft is connected with the prism support, and the other end of the center shaft is connected with a rotary electric cylinder arranged on the sliding block, so that the angle of the prism lens can be changed when the center shaft rotates due to the driving of the rotary electric cylinder.

The driving unit comprises a side pushing electric cylinder, a rotating electric cylinder and a sliding block. A chute is provided on the first face of the prism table, the chute extending along the translation direction (in the figure, the length direction of the prism table). The sliding block is arranged on the sliding groove in a sliding manner. The side pushing cylinder as a translation driver is fixed to the prism table, and moves the slider along the slide groove in the translation direction according to a driving control signal of the control unit. A rotary cylinder as a rotary driver is provided to the slider and rotates the prism unit around a central axis of the prism unit in accordance with a drive control signal of the control unit. The electric cylinder is a driver for converting the rotational motion of the servo motor into linear motion, but the present invention is not limited thereto, and any driver may be used as long as it can precisely control the rotational speed, torque, and position.

The cleaning unit includes a wiper strip and a wiper strip driver. The wiping strip is a member for cleaning stains on the prism lens, but is not limited thereto as long as the prism lens can be cleaned. The wiping strip driver is used for driving the wiping strip to move on the surface of the prism lens so as to clean the prism lens. The damping ball is used for absorbing vibration from the lug detection system or the outside, and avoids imaging degradation such as ghosting and schlieren in imaging, so that a clear lug image can be shot.

Referring to fig. 10, fig. 10 shows a control logic diagram of an exemplary lower computer of a prism apparatus, according to some embodiments of the present application.

In the hardware structure of this embodiment, CSM32RV20 is used as a main control chip, AT8549 is used as a chip for driving a cylinder, HX1314G is used as a power management chip, AMS1117 is used as a main control chip voltage stabilizing chip, CH340B is used as a serial port to USB chip, and PIN4-2.3 is used as a cylinder interface. The connection and configuration of the external devices matched with each component are conventional, and will not be described in detail.

Firstly, a 24V power supply is connected, a power management chip HX1314G reduces the voltage of 24V to 5V and then supplies power to a cylinder driving chip AT8549, a power management chip CH340 serial port is converted into USB, an AMS1117 performs voltage stabilization and constant current chip power supply, and the AMS1117 converts the voltage of 5V into the voltage of 3.3V to supply power to a main control chip CSM32RV20 chip. The upper computer establishes communication with the prism device through the USB interface, the upper computer sends out an instruction of angle deflection of the prism, and the main control chip CSM32RV20 converts the instruction into PWM pulse and sends the PWM pulse into the AT8549 chip to drive the 2-phase 4 wire inserted on the A, B interface. The stepping motor rotates to control and adjust the angle state of the prism, the upper computer sends out an instruction for adjusting the distance between the prisms, and after receiving the instruction, the CSM32 chip converts PWM pulse signals and sends the PWM pulse signals into the AT8549 chip to drive the 2-phase 4-line stepping electric cylinder inserted on the C, D interface to perform telescopic movement, so that the distance between the prisms is controlled and adjusted. Similarly, the E, F interface is connected with a wiping electric cylinder serving as a cleaning driver, and the cleaning effect is achieved by controlling the telescopic movement of the wiping electric cylinder.

In one embodiment, the shooting adjustment of the tab may be achieved by:

step 1, aiming at a certain type of battery, manually controlling a prism unit through a control unit (such as an upper computer) to adjust the prism posture so as to achieve an optimal imaging state;

step 2, quantifying an image definition value serving as an evaluation parameter in the optimal state of the prism in the step 1 through a visual algorithm, and associating the image definition value serving as a first threshold value with the type of the battery for storage;

step 3, after the battery comes or is switched, the control unit firstly controls the prism to reset at a preset angle (for example, 45 degrees), and the prism can be reset at a preset position (for example, centered reset) according to the spacing of the battery lugs;

step 4, the control unit controls the camera to acquire an image, calculates image definition data through a visual algorithm and compares the image definition data with a first threshold value;

step 5. If the difference between the evaluation parameter and the first threshold value is outside the predetermined range, rotating the prism unit in a first rotational direction (e.g. clockwise) and/or moving the prism unit in a first translational direction (e.g. rightward) to increase the pitch, each time by adjusting by a preset angle (e.g. 1 °) and/or a preset distance (e.g. 1 mm);

Step 6. If the sharpness value deviates from the first threshold value by an increased amount after performing step 5, the prism unit is rotated in a second rotation direction (e.g. counterclockwise) opposite to the first rotation direction and/or moved in a second translation direction (e.g. left) opposite to the first translation direction, each time adjusted by a preset angle (e.g. 1 °) and/or a preset distance (e.g. 1 mm);

and 7, executing the steps 5 and 6 until the difference between the definition value and the first threshold value is not out of the preset range.

In one embodiment, the method may further comprise the steps of: and comparing the definition value with a second threshold value, and if the definition value is smaller than or equal to the second threshold value, enabling the cleaning device to clean the prism unit.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the embodiments, and are intended to be included within the scope of the claims and description. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims

1. A tab detection system, the tab detection system comprising:

a control unit that outputs a photographing control signal to the imaging unit and a driving control signal to the driving unit;

the imaging unit is used for shooting the tab through the prism unit according to the shooting control signal to obtain a tab image; and

a prism apparatus, the prism apparatus comprising:

a prism table;

a prism unit that projects an image of the tab to the imaging unit by refraction and is disposed to be movable with respect to the prism table; and

a driving unit for moving and/or rotating the prism unit relative to the prism table according to a driving control signal of the control unit,

wherein the control unit is configured to iteratively perform the following operations until it is determined that the difference between the evaluation parameter of the tab image and the first threshold value is not outside a predetermined range:

sending a shooting control signal to the imaging unit;

calculating the tab image shot by the imaging unit to obtain an evaluation parameter of the tab image; and

in response to determining that the difference between the evaluation parameter and the first threshold is outside a predetermined range, a drive control signal is output to the drive unit to cause the prism unit to move and/or rotate relative to the prism table by a prescribed step size.

2. The tab detection system of claim 1 wherein,

the control unit includes:

the upper computer is used for controlling the imaging unit to shoot the tab image, responding to the tab image shot by the imaging unit, calculating the tab image to obtain an evaluation parameter of the tab image and sending the evaluation parameter to the lower computer; and

and a lower computer, provided in the prism device, for determining whether a difference between the evaluation parameter and a first threshold value is out of a predetermined range in response to receiving the evaluation parameter from the upper computer, and outputting a driving control signal to the driving unit to move and/or rotate the prism unit with respect to the prism table by a predetermined step size if the difference between the evaluation parameter and the first threshold value is out of the predetermined range, and for transmitting a request for requesting the imaging unit to capture an image to the upper computer.

3. The tab detection system of claim 1 wherein,

the driving unit includes:

a translation direction driving device for moving the prism unit along a translation direction; and

and a rotation direction driving device for rotating the prism unit around the central axis of the prism unit.

4. The tab detection system of claim 3 wherein,

the prism table is provided with a chute which extends along the translation direction,

the translational direction driving device includes:

the sliding block is arranged on the sliding groove in a sliding manner; and

a translation driver for moving the slide block along the slide groove in the translation direction according to the driving control signal of the control unit,

the rotation direction driving device includes a rotation driver that rotates the prism unit around a central axis of the prism unit according to a driving control signal of the control unit, and the rotation driver is provided to the slider.

5. The tab detection system of claim 3 wherein,

the translation direction is the length direction of the prism table, and the center axis is perpendicular to the surface direction of the prism table.

6. The tab detection system of claim 4 wherein,

the prism unit comprises a prism support, a prism lens and a center shaft, one end of the center shaft is connected with the prism support, and the other end of the center shaft is rotatably arranged on the sliding block.

7. The tab detection system of claim 1 wherein,

The prism device is further provided with a cleaning device,

the control unit is further configured to:

and outputting a cleaning control signal to the cleaning device to enable the cleaning device to clean the prism unit when the evaluation parameter is smaller than or equal to a second threshold value.

8. The tab detection system of claim 7 wherein,

the cleaning device includes:

a wiper strip in contact with the prism unit; and

and a cleaning driver for moving the wiping strip along a prescribed direction according to the cleaning control signal so as to clean the prism unit.

9. The tab detection system of claim 1 wherein,

the prism device further includes a damper device provided on a first side surface of the prism table, the first side surface being a different side surface from a second side surface on which the prism unit is disposed, and the prism device is fixed to the tab detection system via the damper device.

10. The tab detection system of claim 1 wherein,

the control unit controls the driving unit to reset at least one of a position or a rotation angle of the prism unit with respect to the prism table to a predetermined value before detecting the tab.

11. The tab detection system of claim 1 wherein,

the prism apparatus includes a first prism unit having a first driving unit and a second prism unit having a second driving unit, the first and second prism units being configured to measure positive and negative tabs, respectively.

12. The tab detection system of claim 11 wherein,

the control unit controls the first prism unit and the second prism unit to reset at a preset angle, enables the first prism unit and the second prism unit to be reset at preset positions according to the distance between the tabs, enables the first prism unit and the second prism unit to rotate in a first rotation direction and/or move in a first translation direction to increase the distance in response to determining that the difference between the evaluation parameter and the first threshold is out of a preset range, adjusts at preset angles and/or preset distances each time, enables the evaluation parameter of tab images obtained after the first prism unit and the second prism unit is adjusted to be larger than the difference between the evaluation parameter and the first threshold before adjustment, and enables the first prism unit and the second prism unit to rotate in a second rotation direction opposite to the first rotation direction and/or move in a second translation direction opposite to the first translation direction.

13. The utility model provides a tab detection method, is applied to tab detecting system, wherein, tab detecting system includes control unit, imaging unit and prism device, imaging unit is used for taking a photograph the tab and obtains tab image, the prism device includes: a prism table; a prism unit that projects an image of the tab to the imaging unit by refraction and is disposed to be movable with respect to the prism table; and a driving unit that moves and/or rotates the prism unit with respect to the prism table according to a driving control signal of the control unit, the tab detection method including:

iteratively performing the following operations until it is determined that the difference between the evaluation parameter of the tab image and the first threshold value is not outside a predetermined range:

shooting the tab by the imaging unit to obtain the tab image;

calculating the tab image by the control unit to obtain an evaluation parameter of the tab image; and

in response to determining that the difference between the evaluation parameter and the first threshold value is outside a predetermined range, the prism unit is controlled by a control unit to move and/or rotate relative to a prism stage of the prism apparatus by a prescribed step.

14. The tab detection method of claim 13, the control unit comprising: the upper computer is used for controlling the imaging unit to shoot images; and a lower computer arranged on the prism device,

the tab detection method comprises the following steps:

the upper computer responds to the lug image shot by the imaging unit, calculates the lug image to obtain the evaluation parameter of the lug image and sends the evaluation parameter to the lower computer,

and the lower computer responds to the received evaluation parameters from the upper computer, judges whether the difference between the evaluation parameters and the first threshold value is out of a preset range, outputs a driving control signal to the driving unit to enable the prism unit to move and/or rotate at a specified step length relative to the prism table if the difference between the evaluation parameters and the first threshold value is out of the preset range, and sends a request for requesting the imaging unit to shoot an image to the upper computer.

15. The tab detection method according to claim 13, wherein the prism device further comprises a cleaning device, and wherein when the evaluation parameter is equal to or smaller than a second threshold value, the control unit outputs a cleaning control signal to the cleaning device so that the cleaning device cleans the prism unit.

16. The tab detection method of claim 13 wherein,

the drive unit is controlled by the control unit to reset at least one of a position or a rotation angle of the prism unit with respect to the prism table to a predetermined value before the tab is detected.

17. The tab detection method of claim 13 wherein,

the control unit controls the first prism unit and the second prism unit included in the prism unit to reset at a preset angle, enables the first prism unit and the second prism unit to be reset at preset positions according to the distance between the tabs, enables the first prism unit and the second prism unit to rotate in a first rotation direction and/or move in a first translation direction to increase the distance in response to determining that the difference between the evaluation parameter and a first threshold value is out of a preset range, adjusts at preset angle and/or at preset distance each time, enables the first prism unit and the second prism unit to rotate in a second rotation direction opposite to the first rotation direction and/or move in a second translation direction opposite to the first translation direction in response to determining that the evaluation parameter of tab images obtained after adjusting the first prism unit and the second prism unit is larger than the difference between the tab images and the first threshold value.